Dash-pot for arc lamps



(.No Model.)

- M. J. WIGHTMAN a; H. LEMP.

DASH POT FOR ARG LAMPS. No. 367,081. v Patented July 26, 1887',

::::::::: PHolo-Lithogmphur. Wanhingion, n. cy

Q i UNITED STATES P TENT OFFICE.

MERLE J. WIGHTMAN AND HERMA N LEMP, OF HARTFORD, CONNECTICUT, ASSIGNORS TO THE SOHUYLER ELECTRIC MANUFACTURING COMPANY,

OF CONNECTICUT.

DASH-POT FOR ARC LAMPS.

SPECIFICATION forming partof Letters Patent No. 367,081, dated July 26, 1887.

Application filed August 19, 1886. Serial No. 211,316. (No model.)

To all whom, it may concern:

Be it known that we, MERLE J. WTGHTMAN and HERMANN LEMP, citizens of the United States, residing at Hartford, in the county of Hartford and State of Connecticut, have invented a new and useful Improvement in Are Lamps, of which the following is such a full, clear, and exact description as will enable any one skilled in the art to which it appertains to IO make and use the same.

Our invention relates to means for stead ying the movements of the mechanism employed to feed the carbon in arc lamps, and it relates more particularly to a peculiar form of dashpot for accomplishing this purpose.

The invention consists of a dash-pot composed of two concentric cylinders,one of which is grooved at the surface of the contact and works within the other, thislatter cylinder being recessed,so as to form aeonical depression, perforated at its apex, and having a ball resting in the aforesaid depression. The latter cylinder is provided with a link, which connects it to the pivoted frame-work of thelamp,

carrying the gearing by which the lamp is fed. The cylinders are located above said pivoted frame-work on the opposite side from thefeedlug-magnets.

In the accompanying drawing, forming part 0' of this specification, we have shown our invention as applied to an arc lamp,which has been patented to Hermann Lemp,November 3, 1885, No. 329,461; but it is not necessarily confined to use with any particular form of lamp; neither is it confined to any particular location in a lamp, for it may be used anywhere in an arc lamp where it has the same function as described.

In the drawing the earbon-holder is designated by the letter H, whichintermeshes with the gearing G, located upon a framework, which is pivoted at a point, a, to the supporting-frame F of the lamp. This supportingfraine also carries the magnets M and D, which 5 are located in a'main and derived circuit, respectively, and govern a eore,to which an extension of the pivoted frame-work is loosely pivoted. The pivoted frame-work, carrying the gearing G, also carries a friction-wheel, W,

- upon whioh'bears a friction-brake, B, supported by a piece extending below said pivoted frame-work, which brake is adapted to be tripped off of said friction-wheel by a trip, T, which it comes in contact with as the frame work oscillates to feed the carbon downward. 5 5

So far the construction and operation of the lamp described is the same as that shown in the patent above referred to. It will be observed in this construction that when the core is raised by the main magnet M, and thelamp starts to feed by means of the derived-circuit magnet D, in which the current is now increased while it is decreasing in the main magnet M, there is a tendency of the carbonto feed suddenly, due to the gravitating of the carbonholder. This action is so sudden and instantaneous as to cause the carbons to come so near together that the light will flicker, and this will occurso rapidly that the main magnet will not have a chance to overcome it. It will be noticed that this movement spoken of isindependent of the feeding that takes place by means of the gearing, and that the presentinvention is designed only to obviate the irregularand sudden movement of the pivoted frame- 7 5 work, whose function is to govern the length of the are within certain limits,-the rest of the feed being controlled by the gearing.

Our invention consists in connectingadashpot, consisting of two cylinders, Cand P, the latter of which is grooved,in orderto make it slide more readily in the cylinder C,to the pivoted frame carrying the gearing. These cylinders, constituting the dash-pot,are located on the opposite side of the carbon-holder from the magnets, and are placed above the pivoted frame-work, the latter of which is connected to said pivoted frame-work by means of a connecting-link, Z. The lower cylinder, P, forming the piston,is recessed at its lower interior 9o portion, so as to form a conical depression,and has also at its bottom a perforation, in which a ball or shot, constituting a valve, 27, rests. The upper cylinder is secured to the fixed frame of the lamp by means of a screw, 8, which 5 passes through the framework and through a hole in the end of the cylinder, which it seals, so as to prevent the admission of air. The shot is held by its gravity only over the perforation in the piston P, and allows the same to descend readily, but retards its upward movement, as the air in the cylinder tends to force the valve more closely to its seat; but when the piston falls the air drives the ball from its seat and permits the passage of the air into the cylinder. The shot and cylinders are not made to fit snugly, so that as the piston-cylinder is forced upward an escape of air takes place around the shot and between the cylinders, thus resisting such movement to a certain extent, but not preventing the same.

The dash-pothaving the functions described, it will be seen that it tends to restrain this sudden feed of the carbon, while it in nowise interferes with the sensitiveness of the apparatus.

Having overcome the fault above referred to, it may be said that the action of the feed of the lamp is perfect, as the feed due to the gearing, which is controlled by the friction wheel and brake, may be regulated to any degree of fineness.

Ne do not wish to confine ourselves to the exact construction of dash-pot described, nor to limit the invention to any exact location of the dash-pot; but

WVhat we desire to claim, and secure by Letters Patent, is

1. The combinatiomin an arc lamp, ofa daslr pot consisting of two concentric cylinders, as O P, the latter constituting the pistonand grooved at the surface of contact, a conical depression therein having a perforation in its apex,a globularbody resting in said conical depression and covering said perforation, forming a Valve, 12, and a link, Z, pivotally connected with said piston and the lam p-regulating mechanism.

2. The combination,in an arc la1np,ofa dash-- pot for steadying the movements of the same, consisting ofa cylinder, O,secured to the frame ofthe lamp, a piston, 1?, working in said cylinder,having a conical depression therein, a perforation in said piston, and a shot or globular body resting in said depression and closing said perforation by its own weight, and a connectinglink pivoted to said piston and to the lampregnlating mechanism.

In testimony whereof we have hereunto set ourhands and seals,tliis 27th day of July, 1886,

in the presence of the two subscribing wit- DOSSCS.

MERLE J. WlGI-ITMAN. [11s.] HERMANN LEMP. [L s.)

\Vitnesses:

A. GRAY KILnoURNE, CHAS. A. KELLOGG. 

